1. Field
The present disclosure relates to electric energy generators, and more particularly, to electric energy generators using solar and piezoelectric energy.
2. Description of the Related Art
Nanowires are relatively minute wires having a diameter of several to several hundred nanometers, and are formed by using semiconductor silicon (Si), tin oxide (SnO), gallium nitride (GaN), or the like. A piezoelectric effect is a phenomenon whereby, when dynamic pressure is applied to an insulating crystal, positive charges are generated at one side of the crystal and negative charges are generated at the other side of the crystal. If pressure is applied to an electrically neutral crystal, positive and negative charges are a little polarized and, thus, charges of the same magnitude and different polarities are generated at opposite sides of the crystal. Because of this charge separation, an electric field is generated. Recent research regarding a device for generating electricity by using piezoelectric characteristics of nanowires has been conducted.
As the current energy problem worsens, solar batteries for converting solar energy into electric energy by using a photoelectric effect are attracting attention as a potential new alternative energy source. Solar batteries are divided into batteries using a Si semiconductor and batteries using a compound semiconductor. Additionally, the batteries using the Si semiconductor are divided into a crystalline Si type and an amorphous Si type. When light is incident on a solar battery, electrons and holes are generated in a semiconductor. If the electrons and holes enter an electric field formed as a result of a pn junction, the electrons will move to an n-type semiconductor and the holes will move to a p-type semiconductor, thereby generating a potential difference. In this case, if a load is connected between the p-type semiconductor and the n-type semiconductor, a current will flow through the load.